In order to reduce a nitrogen oxide content in the exhaust gas of an internal combustion engine, exhaust gas post-treatment can be carried out with an aqueous reducing agent solution and a catalytic converter. The aqueous reducing agent solution is, in particular, a urea-containing solution which is injected into what is referred to as an SCR (Selective Catalytic Reduction) catalytic converter. For this purpose, the urea-containing solution is pumped by means of a fluid pump to an injection valve which meters the urea-containing solution upstream of the catalytic converter into an exhaust gas flow into an exhaust gas section of the internal combustion engine. The reducing agent solution preferably reacts in the hot exhaust gas flow to form ammonia and carbon dioxide. In the catalytic converter, the ammonia then reacts with the nitrogen oxide mixture of the exhaust gas to form nitrogen and water. The efficiency of the catalytic converter is influenced by manufacturing-related or storage-related tolerances in the catalytic converter system.
It is desirable to specify a method for operating an exhaust gas catalytic converter which operates reliably. Furthermore, it is desirable to specify an exhaust gas catalytic converter system which is designed to carry out such a method.